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The research leading to these results has received funding from the European Community's Seventh Framework Programme (FP7/2007-2013) under grant agreement N° 305169.
Tools to improve the performance of AfricanSwine Fever surveillance in free countries
RiskSur case studies
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Chapter 1 Chapter 2 Chapter 3 Chapter 4 Chapter 5
ASF has serious and irreversible consequences
No vaccine Erradication in the past:
Cuba Rep. Dom.& Haiti
BR
ES & PT
FR
BE & NL
IT
ASF spread 1960´s-1990’s
Africancountries
Total depopulation: Cuba, Rep.Dom, Haiti, BR, Malta Adequate surveillance and
control of transmissionES, PT: 32-35 yearsIT (mainland): 1967, 1980FR: 1964, 1967, 1974BE: 1985-1986NL: 1986
Malta
Present since 1978 withouttransboundary spread: IT (Sardinia) current erradicationplan (2015-2017)Genotype I 2
Chapter 1 Chapter 2 Chapter 3 Chapter 4 Chapter 5
ASF has serious and irreversible consequences
No vaccine Erradication in the present:
Present with transboundary spread:
Caucasus: since 2007 RF: since 2007 UKR: since 2012 BY: since 2013 UE countries: since 2014 African countries: 22 genotypes
present!
Africancountries
Georgia
ArmeniaAzerbaijan
RUEELVLT BY
UKRPL
Genotype II
FAR AWAY!!!
ASF risk of spread today
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Chapter 1 Chapter 2 Chapter 3 Chapter 4 Chapter 5
What to look for?
Sampling and Testing dead orsick wild boar Sampling and
Testing suspectpig holdings*
BIP Inspectionpersonal luggage
InspectionC&D procedures
Sampling and Testingmeat and products
animal origin
Testing home slaughter
Sampling, Testingand quarantineimported pigs
Sampling and Testing hunted
wild boar
* Suspect pig holdings: with clinical evidence, epi link to ASF+, untreatedswill feeding, probability of exposure, vectors (CD2003/422/EC)
Surveillance components for ASF early detection used in 2013
• ASF tests were carried out only in symptomatic/dead animals
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Chapter 1 Chapter 2 Chapter 3 Chapter 4 Chapter 5
What to look for?
Evaluation of the level of ASF threat
Geographically close
Socio-culturally close
Close by trade
Environmentally close
Connected throughplane or boat
Distance to ASF outbreaksWhat to
look
threat
Routes of introduction
Threat at origin
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Chapter 1 Chapter 2 Chapter 3 Chapter 4 Chapter 5
Where to look for?Mapping of ASF high risk areas in 2013
LithuaniaLatvia
Poland
Only borders with infected countries are considered at high probability of exposure
• Surveillance carried out only in those areas6
Chapter 1 Chapter 2 Chapter 3 Chapter 4 Chapter 5
Evaluation of the routes of introduction and spread For each administrative unit or disaggregated in the country
Assessment of ASF routes of introduction (Mur et al., 2014) according to country-specific scenarios
Where to look?Legal
tradeIllegaltrade Fomites Wild boar
Live pigs Meat and products
What is the probability that at least one infected wild boar survives, moves and enters?What is the probability that wild boar hunters transport the virus elsewhere?
Evaluation of “transport” until destination7
Chapter 1 Chapter 2 Chapter 3 Chapter 4 Chapter 5
(cont.)
For each route of introduction, identify population at risk of exposure For each route of introduction and population at risk, identify
routes of spread, super-spreaders and maintenance characteristics
Evaluation of the routes of introduction and spread
Evaluation of exposure and consequences
Where to look
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Chapter 1 Chapter 2 Chapter 3 Chapter 4 Chapter 5
Pig holdings: classified by biosecurity (proxy: number of pigs/farm) Free-ranging pigs Feral pigs Wild boar shared habitat (proxy abundance) Local spread (direct and indirect):
Distance between and from pig holdingsDistance from wild boar corridorsDistance from free-range pigs
Local and long distance spread(direct and indirect): Contacts between pig holdings
Local and long distance spread (untreated swill feeding): need to know habits!!
Home-killingHunting practicesDistance to slaughterhouses, hotels, ports waste…
Suitability or vulnerability maps For each administrative unit or disaggregated in the country
Where to look
Population at risk(Target population)
Factors that favor spread/maintenance
De la Torre et al., 2014
Evaluation of exposure and consequences
Chapter 1 Chapter 2 Chapter 3 Chapter 4 Chapter 5
Many tools availableMapping of risk factors (adding risk factors or weighted risk factors) Association of risk factors with risk of infection (classical stats,
bayesian) Spatial association of risk factors with risk of infection (cluster
analysis) Transmission potential (SEIR models) with risk factor mapping Etc,etc
Quantitative
Qualitative
Semiquantitative10
Chapter 1 Chapter 2 Chapter 3 Chapter 4 Chapter 5
Risk-based ASF early detection surveillancePlenty of analytical tools available….but not under one
same ToolBox yetWe’re probably a step behind…exploratory tools and
understanding the epidemiology of the disease are equally importantThese tools have to be integrated in the design and
evaluation framework to obtain the best efficiency at theleast cost
Chapter 1 Chapter 2 Chapter 3 Chapter 4 Chapter 5
How to look for ASF?
“The short viremia and high mortality associated with ASF make it virtually impossible to detect the disease through active surveillance”.
Generalized concepts lead to a misconception of the disease epidemiologyi.e. source of virus is not considered
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Chapter 1 Chapter 2 Chapter 3 Chapter 4 Chapter 5
‘Early detection’ at a high biosecurity farm in Lithuania
Antibodies
Estimated date of infection: 3-5 July
ASF suspicion: 21 July ASF confirmat: 24 July
During the high risk period, pigs for slaughter were shipped to Poland
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Chapter 1 Chapter 2 Chapter 3 Chapter 4 Chapter 5
How to look for ASF? “Numbers of found dead animals and number of wild boar sampled
and tested prove the high efficiency and efficacy of the passivesurveillance in the early detection of ASF”
Efficiency measured by number of samplestaken rather than by evaluating a high levelof performance relative to inputs
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Chapter 1 Chapter 2 Chapter 3 Chapter 4 Chapter 5
Cost-effective surveillance programme
Risk ranking transmission scenarios:
Probability of source being infective: amount of infective virus at sourceHigh probability of visible clinicalsigns, particularly if infectiousanimal is symptomatic and susceptible animal is young
Symptomatic and asymptomatic pigs
+++
+
Direct contact with infectedanimalsPigs fed with uncookedinfected meatIndirect contact with fomites(tools, vehicles, clothing,equipment, other animals….)Biological vectors -Ornithodoros ticks
Probability of contact between infective source and susceptible Probability of the susceptible animal developing infection and being infectious
Evaluation of surveillance options according to feasibility and risk of missinginfection early
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Chapter 1 Chapter 2 Chapter 3 Chapter 4 Chapter 5HOW to
look?
Movements
IntraherdEnviron
ment
Concentrationareas
Directcontact
Contaminated feed
Movements
Transport Environment
Directcontact
Contaminated feed
Transport Environment
TICKS
Wild boar-to-farm transmission Farm-to-farm transmission
TRANSMISSION SCENARIOS
CONTROL AND SURVEILLANCE OPTIONS
Avoidmassivehunting
Eliminatinginfected
material (ifpossible)
Live animal testing
Wastemanagement
Heattreatment
Tissuetesting
C&DC&D
Biosec
C&D
Biosec
Paper workcheck
Dead or symptomatic animal testing
Tissuetesting
Live animal testing
Dead or symptomaticanimal testing
Paper workcheck
Logistically challenging
Higher risk of missing ASF infection
Very costly
Improvedinfrastructure
All of the WB-dom measures
Live animal testing
Dead or symptomatic animal testing
Populationstudies
Live animal testing
Dead or symptomatic animal testing
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Chapter 1 Chapter 2 Chapter 3 Chapter 4 Chapter 5
Risk-based ASF early detection surveillance
Identifying areas at higher probability of exposure (probability of becoming an index case)
Identifying consequences (number of secondary cases, duration of outbreaks) for each type of index case
Identifying the number of subjects that need to be covered over a certain time period to ensure detection at 95% confidence level
when where how
Passivesurveillance
Always Whole country Awareness, training, speed,new diagnostic methods
Active surveillance
Increased level of threat
Areas and means depend on transmissionscenarios and consequences!
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The research leading to these results has received funding from the European Community's Seventh Framework Programme (FP7/2007-2013) under grant agreement N° 305169.
ContactProf. José Manuel Sánchez-VizcaínoMarta Martínez Avilés, PhD, MScVISAVET Centre-Universidad Complutense de MadridSPAINwww.sanidadanimal.info
[email protected]; [email protected]
www.fp7-RISKSUR.eu
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